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Biomedical subjects

M J Murphy

Publications and source records attributed to M J Murphy.

At least 145 records · Page 8Linked to original sources
PubMed1987

Nonunion following two-level anterior cervical discectomy and fusion.

Nonunion is a potential complication of anterior cervical discectomy and fusion (ACDF). There are reports that cite the prevalence of nonunion for two-level ACDF with various fusion techniques, but they do not recommend treatment alternatives. Pseudarthrosis after a two-level ACDF occurred in a 69-year-old man. Posterior cervical wiring and autograft resulted in a successful fusion anteriorly and posteriorly. Posterior fusion augments stability, enhances the potential for eventual anterior fusion, avoids the risks of an additional anterior procedure, and is an excellent therapeutic alternative to a second anterior attempt at stabilization.

Aged↗
PubMed1986

Bovine abortion and death associated with consumption of aflatoxin-contaminated peanuts.

Approximately 12% of a herd of 68 crossbred cows aborted third-trimester fetuses after consuming moldy peanuts for 4 days. Further investigation revealed that less than 20% of the herd had access to this supplemental feed. Results of serum biochemical analysis indicated liver damage in the affected cows. All of these cows died within 8 days of aborting. The peanuts contained 77 micrograms aflatoxin B1/g, as determined by liquid chromatography. Tissues were submitted from 1 cow, and liver contained 5 ng aflatoxin B1/g. Results of other laboratory tests were negative for common toxins and abortifacients.

Abortion, Veterinary↗
PubMed1986

Rapid method for permanent slide preparation of colonies in soft agar cultures.

A method is presented for preparing permanent microscopic slides from colony-bearing agar layers in soft agar cultures. The main advantages of this technique are its simplicity, rapidity and accurate colony preservation. This method could have broad applications in the human tumor clonogenic assay (HTCA), particularly in the quantitative morphological, cytochemical and immunocytochemical assessment of colonies that form in both control and drug-treated cultures. Thus, this method opens up possibilities for using cytopathological criteria as a quantitative endpoint of the HTCA.

Agar↗
PubMed1986

Radiology of postnatal skeletal development. XIII. C1-C2 interrelationships.

Composites of C1 and C2 were analyzed in various roentgenographic projections to elucidate osseous interrelationships and the effect of overlap of different portions of these two vertebrae in standard radiographic projections during differing stages of postnatal chondro-osseous transformation. In anteroposterior projections the dentocentral synchrondroses of C2 normally was located below the inferior rim of the C1 anterior ossification center. The upper extent of the dens ossification center was behind this anterior C1 center. The overlap made visualization of the ossiculum terminale difficult. The spinous process of C1 could be confused with the ossiculum. In transverse projections, the normal laxity characteristic of young children allowed considerable variation in rotational interrelationships. Various degrees of such instability are illustrated. In lateral views variation of the anterior contour of the dens was significant. Such variation must be considered developmental due to the location and direction of growth of the chondrum terminale and interactive modeling between C1 and C2 to allow extension at this particular joint.

Axis, Cervical Vertebra↗
PubMed1986

Relationship between histopathology and in vitro clonogenicity in breast cancer.

The human tumor clonogenic assay was used to culture 268 primary and metastatic breast cancer samples. Cultures of 181 specimens were prepared in the double-layer agar system and 87 in a modified system utilizing a liquid upper layer. Successful growth (greater than 5 colonies) was 53% for the agar 2-layer method and 68% for the modified system. Three morphologically distinct colony types were observed: Type I--small, dark, compact colonies; Type II--clear colonies; and Type III--mixed colonies of Types I and II. In 73 cases the histologic slides of the original tumor specimens were reviewed, and the histopathological findings correlated with the clonogenicity of the specimens. There was a significant positive relationship between the degree of differentiation and focal microscopic tumor necrosis in the original specimen and its subsequent clonogenicity. However, other histologic parameters did not show any relationship with clonogenicity.

Breast Neoplasms↗
PubMed1986

Osmoregulatory effects of prolactin and growth hormone in embryonic chicks.

Intact White Leghorn chick embryos were treated daily (on Days 6-13) with bovine prolactin (PRL) or ovine growth hormone (GH) at doses of 4-10 micrograms/g embryo wet wt. A control group received an equal volume of avian saline. [Na+] and [Cl-] were determined in allantoic fluid samples taken on Days 10, 12, and 14, and in amniotic fluid and blood plasma on Day 14. Allantoic fluid, amniotic fluid, and plasma osmolarities, embryo wet weight, hematocrit, and allantoic fluid volume were also determined on Day 14. PRL-treated embryos showed significantly lower allantoic [Na+] and [Cl-] compared to controls at Days 10, 12, and 14. Allantoic fluid osmolarity was reduced, and plasma osmolarity increased, at Day 14 in PRL-treated embryos. By contrast, PRL had no effect on allantoic volume, amniotic fluid [Na+], [Cl-], or osmolarity, plasma [Na+] or [Cl-], hematocrit, or embryo wet weight. GH-treated embryos showed significantly reduced allantoic [Na+] at both Days 10 and 14, but no other treatment effect. Calculations show that the decrease in total allantoic Na+ seen in PRL-treated embryos is equivalent in magnitude to 10% of the total egg Na+. Results from studies on embryonic amphibians and mammals suggest that this sodium is likely to be sequestered in an expanded extracellular volume.

Allantois↗
PubMed1986

Environmental risk assessment of industrial facilities: techniques, regulatory initiatives and insurance.

Most companies that manufacture, handle or dispose of chemicals or petroleum products have the potential to cause environmental impairment, especially by longterm or gradual release of materials into the environment. This impairment creates potential liabilities that result from numerous regulations as well as from common law. One way to identify these potential environmental liabilities and exposures is through environmental risk assessment. The primary focus of an environmental risk assessment is to evaluate the potential for off-site gradual impairment arising from a company's operations. Such an assessment reviews the status of the firm's environmental risk exposure and is a useful internal tool for corporate planning. There are three major objectives in performing an environmental risk assessment: risk identification, risk evaluation and risk reduction. To identify risk, numerous criteria are used to determine the individual factors contributing to the potential for off-site exposure. The interaction of these individual risk factors is then used to evaluate the overall potential for gradual environmental impairment. After the risks have been evaluated, recommendations are made to reduce the potential exposures. In addition, implementation of risk reduction strategies accomplish the objective of legislative initiatives for protecting human health and the environment. Environmental risk management can and should be encouraged through legislative initiatives.

Accidents, Occupational↗
PubMed1986

Neuraminidase and hematopoietic factors from human urine.

Human urinary neuraminidase, an enzyme that releases sialic acid from hematopoietic factors found in urinary preparations, was partially characterized, and a method was developed to derive these hematopoietic factors free of enzyme activity. Neuraminidase in urinary preparations from healthy humans and aplastic anemic (AA) patients had optimal activity at pH 5.3 and hydrolyzed both alpha 2----3 and alpha 2----6 type ketosidic linkages of N-acetyl-neuramin lactose and alpha 1-acid glycoprotein. When subjected to Sephacryl S-300 gel filtration, urinary neuraminidase showed a single peak of activity with an apparent molecular weight of 380,000 daltons, even under denaturing conditions (6 M guanidine hydrochloride). Furthermore, among a variety of compounds tested, no potent inhibitor of the enzyme was found. Heat treatment of AA urinary preparations eliminated about 80% of neuraminidase activity, while successive two-step ethanol precipitation eliminated residual enzyme. Erythropoietin, megakaryocyte colony-stimulating factor (CSF) and granulocyte/macrophage phage CSF activities were retained after these treatments.

Anemia, Aplastic↗
PubMed1986

Colony formation of granulocyte (CFU-g) and macrophage (CFU-m) precursors in serum- and albumin-free culture: effect of transferrin on clonal growth.

Clonal growth of mouse granulocyte and macrophage precursors were assayed in serum-free cultures without albumin. The number of granulocyte/macrophage colonies and clusters increased as transferrin (Trf) concentrations were increased in cultures containing serum-free L-cell-conditioned medium (LCM). On the other hand, cultures with LCM but without Trf produced relatively fewer colonies and clusters. These results indicate that Trf is one of the factors promoting the clonal growth of granulocyte and macrophage precursors in vitro. Although the presence of linoleic acid, alpha-thioglycerol, and dextran in the culture medium increased the number of granulocyte/macrophage colonies and clusters, these factors were not essential. Serum-free culture of mouse granulocyte and macrophage precursors provides a very useful system with which the activity and function of biological regulators of hematopoietic progenitors may be studied.

Animals↗
PubMed1986

Biochemical properties of human urinary megakaryocyte colony-stimulating factor and erythropoietin: the role of sulfhydryl groups and disulfide bonds.

The labeling of cystine residues with [1-14C]iodoacetic acid showed that urinary preparations from patients with aplastic anemia contained 3.06 X 10(-9) mol of sulfhydryl groups and 2.90 X 10(-7) mol of half-cystine as disulfide bonds in the native state, and 6.36 X 10(-7) mol in the denatured state per absorbance unit of protein, respectively. Sulfhydryl reagent-treated proteins retained full activity of megakaryocyte colony-stimulating factor (Meg-CSF) and erythropoietin (Epo), except with DTNB-treated protein. Reduction-carboxymethylation and reduction-mercuration resulted in complete loss of Meg-CSF and Epo activities, suggesting that one of the essential chemical groups of Meg-CSF and Epo is a disulfide bond. Reduction of disulfide bonds at neutral pH revealed that Meg-CSF is less susceptible to reduction than Epo. Reactivation occurred by spontaneous reoxidation in most of the reduced Meg-CSF (92.6%) and part of the reduced Epo (22.1%). These molecular behaviors may reflect differences in the spatial configurations of Meg-CSF and Epo.

Colony-Stimulating Factors↗
PubMed1986

The humoral regulation of megakaryocytopoiesis and platelet production in vivo.

We examined the effects of the urinary extracts from aplastic anemia (AA) patients, idiopathic thrombocytopenic purpura (ITP) patients, and normal subjects on murine megakaryocyte/platelet production in vivo and in vitro. In the first study, single doses of AA urinary protein (65%-90% ethanol precipitate) were individually injected intraperitoneally into rats and mice. Blood platelet counts in rats increased significantly 24 hours after the injection. Total megakaryocyte colony-forming units (CFU-Meg) in mouse spleens increased by 24 hours postinjection, peaked at 48 hours and returned to normal levels at 96 hours. Changes in the number of megakaryocyte colonies showed similar patterns of increasing, peaking and returning to normal levels postinjection. In the second study, we compared the effects of some urinary extracts on murine megakaryocyte/platelet production. These observations provided the evidence that AA urinary extracts contain a factor that directly stimulates megakaryocyte progenitor cell proliferation in mouse spleen in vivo as well as the release of platelets from megakaryocytes, and ITP urinary extracts do not contain increased levels of Meg-CSF and/or some other factor that directly stimulates CFU-Meg in vivo, and the decreased blood platelet mass that is clinically characteristic of ITP is not a primary in vivo determinant of the elaboration of these factors.

Anemia, Aplastic↗
PubMed1986

Posterior cervical fusion with rigid internal fixation.

Rigid fixation of the posterior cervical spine offers definite advantages over conventional wiring techniques. These advantages are emphasized in certain high-risk groups of patients, including those with multiple-level traumatic instability, cervical deformities, and unresectable anterior tumor involvement. Early fusion with minimal external fixation is another important advantage. The focus of this article is the concept of rigid internal fixation of the posterior cervical spine and the application of specific techniques used to achieve this goal.

Adolescent↗
PubMed1985

A comparative study of the interaction of 5,10,15,20-tetrakis (N-methylpyridinium-4-yl)porphyrin and its zinc complex with DNA using fluorescence spectroscopy and topoisomerisation.

Binding of 5,10,15,20-tetrakis (N-methylpyridinium-4-yl)porphyrin (H2TMPyP4+) and its zinc complex (ZnTMPyP4+) to DNA is demonstrated by their coelectrophoresis and by absorption and fluorescence spectroscopic methods. Topoisomerisation of pBR322 DNA shows that H2TMPyP4+ unwinds DNA as efficiently as ethidium bromide showing that it intercalates at many sites. ZnTMPyP4+ may cause limited unwinding. Marked changes in the fluorescence spectra of the porphyrins are found in the presence of DNA. The fluorescence intensity of either H2TMPyP4+ or ZnTMPyP4+ is enhanced in the presence of poly (d(A-T)), whereas in the presence of poly (d(G-C] the fluorescence intensity of ZnTMPyP4+ is only slightly affected and that of H2TMPyP4+ markedly reduced. Both the porphyrins photosensitize the cleavage of DNA in aerated solution upon visible light irradiation.

Animals↗
PubMed1985

Long-term follow-up of seizures associated with cerebral arteriovenous malformations. Results of therapy.

Of 115 patients with angiographically demonstrated cerebral arteriovenous malformations (AVMs), seizures occurred in 66 (57%), all of whom had supratentorial AVMs. Seizures were the initial manifestations in 36 patients. In 14 patients seizures developed within 30 days of hemorrhage or surgical resection; in 16 others seizures started within 0.5 to 16 years after hemorrhage or resection. Seizures were infrequent in the majority of patients; in only nine (16%) were they incapacitating. Among 46 patients observed from two to 36 years, 23 (50%) were seizure free for a minimum of two years at follow-up. Neurological deficits on examination and previous occurrence of hemorrhage did not adversely affect seizure control. No significant difference was found between the percentage of seizure-free patients in the medical and surgical groups at follow-up. Irrespective of treatment method, seizures starting within 30 days of hemorrhage or resection had the best prognosis.

Adolescent↗
PubMed1985

Differential identification of mouse granulocyte (CFU-g) and macrophage (CFU-m) precursors in plasma clots.

Because benzidine and its derivatives have possible carcinogenic activity, a safe method is needed to demonstrate endogenous peroxidase activity. Colonies derived from mouse bone marrow cells in plasma clot culture were classified as granulocyte (CFU-g) or macrophage (CFU-m) precursors by peroxidase and naphthol AS acetate (NASA) esterase staining, respectively. Endogenous peroxidase activity was measured using benzidine or p-phenylenediazine-pyrocatechol (PPD-PC). The effectiveness of peroxidase staining with both reagents was evaluated under several conditions, and the enzyme property was confirmed by inactivation with a variety of inhibitors. The level of peroxidase activity did not differ significantly between PPD-PC and benzidine. Colony number and number of cultured cells were strongly correlated (P greater than 0.983). We conclude that PPD-PC safely demonstrates peroxidase activity in cultured cells and is as accurate, reliable, and efficient as benzidine.

Animals↗
PubMed1985

Improvements in glass capillary gas chromatographic polychlorobiphenyl analysis.

Separation of a 1:1:1:1 calibration mixture of Aroclors 1221, 1016, 1254, and 1260 on soda glass capillaries coated with Apolane (C-87) or Apiezon L is described. Polychlorobiphenyl congener structures are assigned to 112 separated and partially separated zones. The quantitative composition of Aroclor 1221 is reported. The performance of the two stationary phases on different lengths of laboratory and commercially prepared capillaries is compared and found to be very similar. Aroclors 1221, 1016, 1254, and 1260 are employed (1:1:1:1) for the primary calibration mixture because they contain all components of the commercial materials which pollute the environment; they are also easily obtained from the U.S. EPA Repository so that the method can be used in any laboratory by employing the calibration data given here.

Chromatography, Gas↗
PubMed1985

Acquisition and clonal growth of human sternal bone marrow obtained incidental to open-heart surgery.

The establishment of a convenient method of acquiring ample human bone marrow and the successful growth of hematopoietic precursor cells in standard methylcellulose assay is described. Human sternal marrow curettings were obtained at open-heart surgery. Growth of colonies derived from CFU-gm, BFU-e, and CFU-e was successful. Comparison of the CFU-gm colony production between this and prior studies indicates a consistent mean and range of growth. These results document this to be an efficient source of normal human marrow.

Bone Marrow Cells↗